Foldable head restraint

ABSTRACT

A foldable head restraint has two head restraint supports set within a bracket. A latch is made integral with at least one of the head restraint supports. The latch rests against a stop to prohibit rotation of the head restraint support in a first direction. The latch rests against a rotational cam to prohibit movement of the head restraint support in a second direction. By rotating the cam, the head restraint support may be folded. The head restraint support is comprised of a metal substrate with over-molded plastic geometry to accept a mating part configured within the head restraint bun. The geometry of the metal substrate and over-molded plastic geometry allow for a reduction, or even elimination, of the slots that are normally required for such a folding head restraint. This ability to fold can yield greater rearward visibility and aid in the kinematic motion of the seat.

BACKGROUND OF THE INVENTION

The invention relates generally to vehicle head restraints and moreparticularly to foldable vehicle head restraints.

Head restraints protect a vehicle occupant from serious injury due tosudden movement of the vehicle. The head restraints generally extendupward from the seat.

While the head restraints are necessary to insure the safety ofpassengers, at times the head restraints can present difficulties. Headrestraints can obstruct the driver's view when looking rearward. If aseat is folded forward to allow a passenger to enter the rear portion ofa vehicle, the head restraint may contact an object in front of the seatthus stopping the seat from fully folding down. In vehicles with seatsthat fold flat into the floor, the head restraint must be removed oradditional stowage space in the floor of the vehicle must be provided.

A foldable head restraint has been described in U.S. patent applicationSer. No. 10/672,703, assigned to the assignee of this patentapplication. A foldable head restraint has a design position where thehead restraint is generally upright and serves as protection for avehicle passenger. The foldable head restraint also has a foldedposition, where the head restraint is rotated to allow completekinematic movement of the seatback, or to increase rearward visibility.

While foldable head restraints offer advantages over non-foldable headrestraints, foldable head restraints are generally more difficult toassemble and therefore relatively more expensive. A foldable headrestraint which is easier to manufacture and less expensive is thusdesirable.

SUMMARY OF THE INVENTION

A foldable head restraint has two head restraint supports set within abracket. The head restraint supports are comprised of a metal substrateand a section of an over-molded geometry. The over-molded geometry isgenerally plastic. A latch is made integral with the metal substrate.The latch rests against a stop to prohibit rotation of the headrestraint support in a first direction and rests against a rotationalcam to prohibit movement of the head restraint supports in a seconddirection. A user rotates the cam to an open position to allow the headrestraint supports to be pivoted to a folded position. To reduce thesize of the slots in the seatback which are often provided toaccommodate foldable head restraints, the head restraint supports have ageneral shape of a “J”. Other shapes and configurations are possible.

The metal substrate of the head restraint supports could be fineblanked, precision stamped, or manufactured by a close tolerance metalfabrication process thereby significantly reducing the cost of the headrestraint support. The metal substrate can then be over-molded. Theover-molded shape and cross-section can be varied as needed to allowmating of the head restraint supports with components found in the headrestraint bun.

The head restraint supports for the primary side and the secondary sideof the head restraint are identical, allowing for ease of massproduction. Also, due to the geometry of the metal substrate andover-molded geometry the package size of the head restraint supports ismore compact when compared to similar mechanisms.

These and other objects, advantages, and features of the invention willbe more readily understood and appreciated by reference to the detaileddescription of the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the primary side of the foldable headrestraint.

FIG. 1A is another perspective view of the secondary side of thefoldable head restraint.

FIG. 2 shows a head restraint support used within the foldable headrestraint.

FIG. 3 is a side view of the foldable head restraint in the designposition.

FIG. 4 is a side view of the foldable head restraint as the cam is beingdisengaged from the rotational lock.

FIG. 5 is a side view of the foldable head restraint in the foldedposition.

FIG. 6 is a side view of the foldable head restraint when it firstcontacts the rotational cam when returning to the design position.

FIG. 7 is a side view of the foldable head restraint before it returnsto the design position.

FIG. 8 is a side view of the foldable head restraint contained within aseat and a bun.

FIG. 9 is a cross-section of the foldable head restraint support.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 shows foldable head restraint 5 viewing the primary side offoldable head restraint 5. Head restraint 5 includes bracket 10. Twohead restraint supports 12, 14 are attached to bracket 10 and arerotatable within bracket 10. A bun is usually provided on head restraintsupports 12, 14. FIG. 1A shows a view of the secondary side of headrestraint 5. Head restraint support 14 also contains latch 22. Bracket10 also includes stop pin 32 and stop pin 17.

FIG. 2 shows head restraint support 12. (Head restraint support 14 isidentical in construction to head restraint support 12.) Over-moldedgeometry 16 of head restraint support 12 is attached to metal substrate18. Over-molded geometry 16 is usually contained within a head restraintbun. Metal substrate 18 of head restraint support 12 includes pivot hole20. Pivot hole 20 is configured so as to be capable of receiving pivotshaft 24, shown in FIG. 1. Rotational torsion spring 7 is placed aboutthe middle of pivot shaft 24. Stabilizer hole 26 is configured so as tobe capable of receiving stabilizer shaft 28, as shown in FIG. 1. Latch22 protrudes from metal substrate 18. FIG. 2 shows surface 25, surface27, and surface 29 of latch 22.

As shown in FIG. 1, latch 22 interacts with rotational cam 30 and stoppin 32 to provide the unique folding ability of head restraint 5.Rotational cam 30 has cam torsion spring 34 installed in a preloadedcondition on cam pin 36. One end of cam torsion spring 34 is held bycable pin 38. Cam pin 36 and cable pin 38 are located on cam 30. Theother end of cam torsion spring 34 is attached to bracket 10.

Cable wire 40 is also attached to cable pin 38. Cable wire 40 is part ofcable 42. One end of cable 42 is attached to cable termination 44, whichis normally integral to bracket 10. The other end of cable 42 may beattached to the vehicle body or to some other device, such as a manualrelease lever, in order to actuate the folding mechanism of headrestraint 5.

FIGS. 3, 4 and 5 show the operation of the head restraint. FIG. 3 is aside view showing the head restraint in the design, or upright,position. Rotational cam 30 holds latch 22 securely against stop pin 32.Stop pin 32 is engaged with latch surface 27. The end of rotational cam30 and latch surface 25 are generally designed such that when headrestraint 5 is in the design position, there is firm engagement betweenthe two, thereby minimizing chuck.

FIG. 4 is a side view showing the head restraint after sufficienttension has been exerted on cable wire 40 to move rotational cam 30.When sufficient tension is exerted on cable wire 40, cable pin 38 ispulled downward toward cable termination 44, causing rotational cam 30to rotate. When rotational cam 30 has rotated sufficiently, latch 22 isno longer held against stop pin 32. Thus, head restraint supports 12, 14are free to rotate toward the folded position.

The angle of head restraint supports 12, 14 relative to a vertical planecan be selected such that head restraint supports 12, 14 willimmediately rotate toward the folded position when rotational cam 30 hasrotated sufficiently to free latch 22 due to the force exerted on headrestraint supports 12, 14 by torsion spring 7. Alternatively, the headrestraint 5 could be designed such that some other force would need tobe applied to head restraint supports 12, 14 to cause head restraintsupports 12, 14 to rotate to the folded position.

FIG. 5 shows head restraint 5 in the folded position. In the foldedposition head restraint supports 12, 14 are near horizontal. Thus, thehead restraint is neither a visual obstruction nor an obstruction duringthe kinematic movement of the seat. When tension is no longer applied towire 40, torsion spring 34 causes rotational cam 30 to return to aposition that will enable it to reengage the lock on latch 22.

To return head restraint 5 to the design position, a force is applied onhead restraint supports 12, 14 usually through the head restraint bun.Head restraint support 12 rotates until latch 22 strikes rotational cam30. Referring against FIG. 6, continued force applied to head restraintsupport 12 causes rotational cam 30 to rotate clockwise.

FIG. 7 shows the position of head restraint 5 just prior to returning tothe design position. Rotational cam 30 has been rotated, causing latchsurface 29 to be in contact with rotational cam 30. At this position,latch surface 29 is constructed such that it will allow the rotationalcam 30 to clear the path of the rotating latch 22.

When a further force is applied to head restraint support 12, latchsurface 29 causes rotational cam 30 to rotate further so that latch 22can come to rest against stop pin 32. Due to the configuration of thesurfaces of latch 22, head restraint support 12 is then locked into thedesign position by contact between rotational cam 30 and latch surface25.

Metal substrate 18 can be fine blanked, precision stamped, or closetolerance metal fabricated component, and would preferably be made of ahigh strength steel. Metal substrate 18 can be over-molded. By varyingthe design of the over-molded geometry, head restraint support 12 couldeasily mate with a variety of head restraint buns. Rotational rod 24 andstabilizer shaft 28 are usually steel rods.

Bracket 10 is usually contained within a seat back. Head restraintsupports 12, 14 extend through the top of the seat back through a pairof slots. In order to minimize the size of these slots, head restraintssupports 12, 14 have the shape of a “J”. Other shapes can be used forhead restraint supports 12, 14 depending upon the particularapplication.

Assembly of head restraint 5 is simple. Head restraint supports 12, 14are first joined by stabilizer shaft 28, and this assembly is thenplaced within bracket 10. Rotational rod 24 is inserted through bracket10 and through head restraint supports 12, 14.

FIG. 8 shows head restraint 5 contained within seat 50 and bun 52. FIG.9 shows a cross-section of rod 16 at 9-9. Rod 16 is shown having steelportion 54 with plastic over-molding 56. The cross-section of steelportion 54 is generally rectangular and the cross-section rod 16 whenfitted with over-molding 56 is generally circular, although other shapesmay be utilized with the same intent and functionality.

The above description is of the preferred embodiment. Variousalterations and changes can be made without departing from the spiritand broader aspects of the invention as defined in the appended claims,which are to be interpreted in accordance with the principles of patentlaw including the doctrine of equivalents. Any references to claimelements in the singular, for example, using the articles “a,” “an,”“the,” or “said,” is not to be construed as limiting the element to thesingular.

1. A foldable head restraint which comprises a first head restraintsupport having a first elongate portion for receiving a bun thereon; abracket; a latch mechanism; a torsion spring that biases a rotationalcam in the first direction; and cable pin to which a first end of thetorsion spring is attached, the latch mechanism including the rotationalcam that can be selectively rotated independently of the first headrestraint support between a latched position in which a second portionof the first head restraint support is engaged by an end surface of therotational cam and thereby locked against pivotal movement and anunlatched position in which the second portion of the first headrestraint support can pivot immediately over the rotational cam.
 2. Thefoldable head restraint of claim 1, wherein the torsion spring has asecond end that is attached to the bracket.
 3. The foldable headrestraint of claim 2, wherein the rotational cam is installed on a campivot pin and the torsion spring is mounted on the cam pivot pin.
 4. Thefoldable head restraint of claim 3, wherein the cable pin is located atthe first end of the rotational cam and the cam pivot pin is located atthe second end of the rotational cam.
 5. The foldable head restraint ofclaim 4, further comprising a second stop, the second stop attached tothe bracket.
 6. The foldable head restraint of claim 5, wherein thesecond head restraint support has a structure that engages with thesecond stop to prohibit motion of the second head support in a firstdirection.
 7. The foldable head restraint of claim 6, wherein thebracket has a first side and a second side with the first stop locatedon the first side and the second stop located on the second side.